Connect to REST Data in CloverDX (formerly CloverETL)

The CData JDBC Driver for REST enables you to use the data transformation components in CloverDX (formerly CloverETL) to work with REST as sources and destinations. In this article, you will use the JDBC Driver for REST to set up a simple transfer into a flat file. The CData JDBC Driver for REST enables you to use the data transformation components in CloverDX (formerly CloverETL) to work with REST as sources and destinations. In this article, you will use the JDBC Driver for REST to set up a simple transfer into a flat file.

Connect to REST as a JDBC Data Source

1. Create the connection to REST data. In a new CloverDX graph, right-click the Connections node in the Outline pane and click Connections -> Create Connection. The Database Connection wizard is displayed.
2. Click the plus icon to load a driver from a JAR. Browse to the lib subfolder of the installation directory and select the cdata.jdbc.rest.jar file.
3. Enter the JDBC URL.

   See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models REST APIs as bidirectional database tables and XML/JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.

   After setting the URI and providing any authentication values, set Format to "XML" or "JSON" and set DataModel to more closely match the data representation to the structure of your data.

   The DataModel property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

   • Document (default): Model a top-level, document view of your REST data. The data provider returns nested elements as aggregates of data.
   • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
   • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

   See the Modeling REST Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

   Built-in Connection String Designer

   For assistance in constructing the JDBC URL, use the connection string designer built into the REST JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

   java -jar cdata.jdbc.rest.jar

   Fill in the connection properties and copy the connection string to the clipboard.

   A typical JDBC URL is below:

   jdbc:rest:DataModel=Relational;URI=C:/people.xml;Format=XML;

Query REST Data with the DBInputTable Component

1. Drag a DBInputTable from the Readers selection of the Palette onto the job flow and double-click it to open the configuration editor.
2. In the DB connection property, select the REST JDBC data source from the drop-down menu.
3. Enter the SQL query. For example: SELECT [people].[personal.age] AS age, [people].[personal.gender] AS gender, [people].[personal.name.first] AS first_name, [people].[personal.name.last] AS last_name, [vehicles].[model], FROM [people] JOIN [vehicles] ON [people].[_id] = [vehicles].[people_id]

Write the Output of the Query to a UniversalDataWriter

1. Drag a UniversalDataWriter from the Writers selection onto the jobflow.
2. Double-click the UniversalDataWriter to open the configuration editor and add a file URL.
3. Right-click the DBInputTable and then click Extract Metadata.
4. Connect the output port of the DBInputTable to the UniversalDataWriter.
5. In the resulting Select Metadata menu for the UniversalDataWriter, choose the people table. (You can also open this menu by right-clicking the input port for the UniversalDataWriter.)
6. Click Run to write to the file.